This invention relates to automatic butchering equipment and more particularly to such equipment for butchering various edible crabs.
Although there has been some effort to automate the butchering process for crabs, most crabs are still presently butchered by hand. The process usually includes the steps of removing the back or carapace from the crab, eviscerating the body cavity, removing the pincers and walking legs, and finally removing the meat from the body and leg cavities. The step of removing the meat from the body cavities is eliminated where the crab sections are to be sold whole.
Various commercial apparatus have been provided to automatically perform the steps of removing the crab meat from the shell. Such machines generally use rollers to press the meat from the body cavities and a salt solution to separate the flesh from the hard shells by flotation. The present invention is concerned primarily with the problem of automatically de-backing, eviscerating, and removing the legs of successive crabs in rapid succession to produce clean crabs for either outright purchase or as a preparation step to the processes performed by such meat-removal machines.
U.S. Pat. No. 3,569,310 to Tolley discloses a crab processing machine. It includes a carriage on an endless chain conveyor. The carriage is adapted to receive crabs of different size and includes integral cutting members for removing the crab carapace. The carcass is cut longitudinally into two sections by a saw on the general framework adjacent the working flight of the conveyor.
Another U.S. Pat. to Tolley, No. 3,495,293, discloses a machine for preparing a hard-shell crab for meat removal. In the Tolley machine, crabs are moved with their carapaces facing upwardly, by conveyor lugs of an endless chain conveyor. A de-backing claw is mounted to a stationary framework for engaging each carapace at a frontal portion thereon and pulling it rearwardly and upwardly from the crab carcass. The loose carapace is then to fall downwardly through the conveyor mechanism. Legs are removed by a rotating wheel having blades thereon and the viscera is brushed away by an overhead rotating brush that is specially contoured to the configuration of the crab body.
U.S. Pat. No. 3,302,263, to S. G. Harris shows a series of independent conveyors that move successive crabs through processing stations. The crabs start the processing on a first conveyor where they are placed in a carapace-down position. Clamps hold the crabs by the carapace and ventral sides of the shells as they move past sets of longitudinal beaters. The beaters operate to rapidly strike the legs and eventually tear the legs free of the carcasses. The crab bodies are then shifted to a second conveyor where they are inverted to carapace-up positions. It is along this conveyor that the carapace is lifted up and off of the crab carcasses by upwardly inclined stationary legs adjacent the working flight of the second conveyor.
U.S. Pat. No. 3,611,478 to W. L. Lockerby shows an apparatus for cutting crab bodies. It includes an endless conveyor similar to the above described apparatus in that it engages the crab carcasses from below and moves them along a prescribed path past a circular saw. It is intended that the carapace be removed prior to operation of the Lockerby device since its only purpose is to section the carcass down the longitudinal or midsagital plane.
It is a principal object of this invention to provide a high speed crab butchering machine that is capable of handling in excess of 1000 crabs per hour.
It is an additional object of the present invention to provide a high speed crab butchering machine wherein the carcasses are operated upon in an inverted position (with the carapace facing downwardly) by an overhead conveyor assembly such that the carapaces may fall freely from the crab carcasses and therefore will not interfere with normal operation of the butchering machine.
It is a further object to provide such a machine that includes a drive mechanism that is controlled to speed movement of the successive crabs between work stations and to slow movement of successive crabs as they proceed through the work stations.
A still further object is to provide such a device that includes viscera removing means that will effectively remove viscera from the successive crab carcasses without damaging the adjacent edible flesh.
A still further object is to provide such a machine that may move successive crabs in a continuous non-stop movement of varying speed to further optimize operational speed of the machine while maintaining operational effectiveness.
These and still further objects and advantages will become apparent upon reading the following detailed description which, taken with the accompanying drawings, disclose a preferred form of our invention. It is noted that the following description and attached drawings are given only as a preferred example of the present invention and are not intended in any way to restrict the scope thereof. The scope is set out only in the claims attached at the end of this specification.